log-det-jacobian.
*   Fix `tf.random_gamma` incorrectly handling non-batch, scalar draws.
*   Resolved a race condition in TensorForest TreePredictionsV4Op.
*   Google Cloud Storage file system, Amazon S3 file system, and Hadoop file
    system support are now default build options.
*   Custom op libraries must link against libtensorflow_framework.so (installed
    at `tf.sysconfig.get_lib()`).